Is Kikuchi-Fujimoto disease a manifestation of systemic lupus erythematosus?

A 32-year-old woman presented with fever and swelling in the axillae of 2 months' duration, and erythema of the face, fluid-filled lesions on the trunk, oral ulcers, crusting of the lips, and redness and watering of the eyes for 3 days. The patient was initially diagnosed with tuberculous lymphadenitis and was given antituberculous treatment. One month later, she developed the present complaints (see below). The patient was photosensitive. There was no joint pain or Raynaud's phenomenon. She had experienced three intrauterine deaths in the past with no live births. On examination, the patient was pale. Bilateral axillary lymphadenopathy was present. The lymph nodes were mobile, non-tender, and not matted. Mucocutaneous examination revealed a malar eruption, flaccid bullae on the back (Fig. 1), crusting of the lips (Fig. 2), oral ulcers, and redness and discharge from the eyes. On investigation, immunoglobulin G (IgG), IgM, and IgA for tuberculosis were negative. There was anemia and leukopenia, the erythrocyte sedimentation rate (ESR) was raised, albumin in urine was positive, enzyme-linked immunosorbent assay (ELISA) for human immunodeficiency virus (HIV) was negative, and venereal disease research laboratory (VDRL) test was nonreactive. Antinuclear antibody (ANA), dsDNA, and antiphospholipid antibody were positive. Fine needle aspiration cytology (FNAC) of the axillary lymph node showed loss of nodal architecture. The extensive infiltrate consisted of lymphocytes, histiocytes, immunoblasts, and necrosis of cortical and paracortical areas. There was histiocytic necrotizing lymphadenitis without granulocytic infiltration. These features were suggestive of Kikuchi-Fujimoto's disease (Fig. 3). Skin biopsy showed epidermal atrophy, basal cell vacuolation, focal hyperkeratosis, pilosebaceous atrophy, and follicular plugging. The dermis showed edema and a lymphocytic infiltrate in the upper dermis and around the blood vessels. These features were suggestive of systemic lupus erythematosus (SLE). Direct immunofluorescence of lesional skin showed a strong continuous basement membrane zone (BMZ) band of C3 and fibrinogen and a strong discontinuous granular BMZ band of IgG. IgA was negative. Covered skin showed moderate and strong positivity for IgM and IgG, respectively. C3, IgA, and fibrinogen were negative. These findings were suggestive of SLE (Fig. 4). Based on the clinical findings and investigations, a diagnosis of Kikuchi-Fujimoto's disease with SLE was made.